Only essential travellers are now allowed into South Australia from Victoria.
Tighter border restrictions kicked in at midnight, preventing non-essential travel from Victoria into South Australian including local residents returning home.
Police Commissioner Grant Stevens said SAPOL officers are ready to catch anyone who tries to illegally enter SA.
"We accept the possibility that's going to be the case but with the resources we have there and some of the technology we're using, we'd expect that we'd catch those people," Commissioner Stevens said.
An exception for the Cross Border Travel No 9) (COVID-19) Direction exists for a person escaping or dealing with circumstances arising from domestic violence or providing support to a family member who is experiencing domestic violence.
The requirement for COVID-19 testing has expanded to include all classes of Essential Travellers, except for those passing through.
All existing directions, frequently asked questions and other information can be found here: https://www.covid-19.sa.gov.au/emergency-declarations
Third SA COVID-19 Case Confirmed and Contained
There has been one new cases of COVID-19 recorded on Tuesday 28 July, bringing the state's total active cases to three.
A woman in her 20s tested positive late Monday after arriving from Victoria with her family to start a new job.
She and her family are in quarantine.
SA's Chief Public Health Officer Nicola Spurrier said she is confident SA's latest confirmed case of COVID 19 has been contained.
"There is no risk at all to the South Australian public from this case," Professor Spurrier said on Tuesday 28 July.
More than 212,000 tests have been undertaken since the start of the pandemic, 441 people have been cleared of COVID-19 and there have been four reported deaths.
Photo SAPOL, supplied